The wild relatives of soybean [Glycine soja Sieb. and Zucc.] have curly/wavy nature whereas cultivated varieties are upright. Such morphological characteristics have agronomic importance too. To investigate the molecular mechanism of development contributing to coiled morphology, screening was carried out to look for Arabidopsis mutants in activation tagging lines obtained by activation T-DNA treatment that have curly/wavy morphology. A mutant named Coiled Branch 1 (cbr1), is found to have a wavy and curly morphology with coiling branches. Plasmid rescue and genomic southern blot analysis revealed the site of T-DNA insertion in the genome. RT-PCR was performed to monitor expression levels of the genes adjacent to the T-DNA integration sites, and showed the activation of an E3 ubiquitin ligase gene. Database search showed that the gene with the RING domain belongs to a family of E3 ubiquitin ligases. Complementation test by overexpression and RNA interference of the gene was also carried out. The complementation test results showed that the novel gene activation tagging affected the cbr1 mutant phenotypes. Ubiquitylation has been linked virtually to every cellular process including plant development. E3 ubiquitin ligase has been reported to recognize target proteins that are to be ubiquinated for further degradation by the proteasome complex. Further, more detailed studies are needed to identify the specific substrate(s) of the novel E3 ubiquitin ligase gene.

Soybean [Glycine max (L.) Merr.] seeds are abundant in high-quality proteins and fats. In addition, soybean seeds are also rich in secondary metabolites, such as isoflavones, lecithin, and saponins. Triterpene saponins are major components of these physiologically active metabolites in soybean seeds. Soybean saponins are classified as group A and DDMP saponins. Among them group A saponins are undesirable component of food products due to bitterness and astringency and also cause foaming in tofu production. Whereas, DDMP saponins and their derivatives are less bitter and astringent and beneficial to human health when consumed as regular diet. Therefore, reducing the group A saponins or increasing the DDMP saponins are required to improve the food quality. The present study focused to identify and characterize the gene which is encoding a protein responsible for biosynthesis of DDMP saponins. EMS mutant lines (sg-7-1 & sg-7-2) which lack DDMP saponins were developed. The breeding cross has been made with these two mutants with two cultivars, Pungsannamul and Wooram to study the segregation and genetic linkage analysis, respectively. The segregation analysis showed that the mutant phenotype is controlled by single recessive gene. TLC analysis for phenotyping F2 population of Wooram X sg-7-1 showed mutant, wild and heterozygous types. To surprise two more patterns were detected and they were named as strange type1 (ST1) and strange type2 (ST2). Further, SSR marker analysis will be carried out to locate the gene which encoding a protein responsible for biosynthesis of DDMP saponins.

Soybean germplasm have diverse accessions with great variation in their ability to survive and reproduce under salt stress conditions. In general, cultivated soybeans are more sensitive to salt stress than their wild relatives, however exceptions are found in both the groups. These variations in response to salt stress makes soybean germplasm an interesting collection of genetic resources to be explored for the identification of salt-tolerance genes, and their mechanism of action. Here, in this report we presented a data showing differential response of selected accessions of both cultivated and wild soybeans to salt stress. Two modes of salt treatment; gradual salt stress (GS) as well as salt shock (SS) were used in this study. The GS was found more effective in finding the difference in response of soybean accessions to salt stress. Various genetic marker based methods are in use to identify and isolate the potential genes contributing to the salt tolerance in soybean. Even then there is a paucity of knowledge on the key genes contributing to the salt tolerance in soybean. We expect that a recently developed functional screen based method, like yeast based functional screen, using cDNA library generated from different salt tolerant accessions of soybean could lead to identification of novel genes responsible for salt tolerance in soybean. Also, we propose for the use of RNA isolated from different stages of GS and SS for making cDNA library to be used for functional screening.

Soybean [Glycine max (L.) Merr.] have a variety of flower colors which are controlled by six different genes (W1,W2,W3,W4,Wm, and Wp). Among these genes, mutation in W3 gene causes near white flowers in the background of w4 genotype whereas the genotype W3w4 does purple throat flowers. Earlier studies showed that dihydroflavonol 4-reductase1 (DFR1) gene was closely linked to the flower color variants for W3 locus. In order to find out the W3 gene responsible for w3 phenotype, we first, studied the candidate gene Glyma14g07940 (DFR1) which is having 100% similarity with DFR probe sequence. Sequence analysis of DFR1 between W3 and w3 soybeans showed one base substitution in exon 6 of w3 mutant soybean resulting in one amino acid change in the amino acid sequence. However, comparison of amino acid sequences of DFR proteins from various crop plants showed that there is no functional change in the protein. Besides, the promoter analysis showed that, 311 bp of indel was traced in 5’-upstream promoter region of DFR1 gene in the w3 mutant. Here, we show that the near white or purple throat phenotypes in G. max is associated with existence or nonexistence of indel at 5’- upstream promoter region and low or high expression of DFR1, respectively. These results suggest that w3 phenotype may be caused by certain regulator of DFR1 gene located near or distant from DFR1 in G. max. In further study, we need to check the correlation between promoter indel with W3 expression level through GUS analysis.

Methane production from grain dust was studied using a 3 L laboratory-scale anaerobic plug flow digester. The digester was operated at; temperature of 35, 45, and 55℃ hydraulic retention time(HRT) of 6 and 12 days; and influent concentration(S_0) of 7.8 and 9.0 % total solids(%TS). With ten different operation conditions, this study showed the significant effects of temperature, hydraulic retention time, and influent concentration on methane production, The highest methane-production rate achieved was 1.903 (L methane) /(L digester)(day) at 55℃, 6 days HRT, and S_0 of 7.8 %TS. A total of 3.767 L of biogas per day with a methane content of 50.57% was obtained from this condition. The ultimate methane yield(B_0 was found to be a function of temperature and influent concentration, and was described as : B_0= 0.02907T-0.1263-0.00297(T-10)(%TS), where TS is the total solids in the liquid effluent, and T is temperature(℃). Our results showed that thermophilic condition is better than mesophilic for grain dust stabilization in an anaerobic plug flow digester.